


so enjoy your life

by adamantine



Category: Voltron: Legendary Defender
Genre: Alpha Shiro (Voltron), Alpha/Beta/Omega Dynamics, M/M, Non-Consensual Body Modification, Omega Keith (Voltron), canonverse except for fuck S8, sort of... ABO only exists for the Galra except...
Language: English
Status: Completed
Published: 2020-01-01
Updated: 2020-01-01
Packaged: 2021-02-27 05:40:06
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 4,493
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/22061947
Author URL: https://archiveofourown.org/users/adamantine/pseuds/adamantine
Summary: Keith is an adult way past puberty when he finds out about the Galra's birds and bees. He's an omega, which kind of sucks but also doesn't. It's a fact about himself he doesn't plan on telling anyone else since it's not really any of their business.Until he starts dating Shiro.Written for @AlexAbrhmDraws on twitter for Sheith Secret Santa 2019! :)
Relationships: Keith/Shiro (Voltron)
Comments: 31
Kudos: 334





	so enjoy your life

**Author's Note:**

> A few other warnings: Mpreg possible universe but no breeding kink or similar makes it into this. (Spoiler) Noncon ABO elements sort of mentioned/implied as something Shiro might have witnessed or learned about while in captivity, but no graphic details are given.

The first video Keith stumbles upon is an accident.

After he presented, Krolia gave him a basic clinical overview of his biology, assuring him he can always reach out to her if he has any other questions.

“What you’re going through is normal,” she promises, the patient mother explaining his body’s changes. “There are, uh, tools that I understand can help.”

Krolia isn’t an omega; she’s a beta which means she adapts to a specific partner’s needs, a detail Keith never wanted to know. He understands now why the Galra have proliferated across the universe and why there are so many half-Galra running around despite the Empire’s views on interspecies relationships.

“If you’re interested I can help arrange the purchase of—”

“No!” Keith is mortified in a way he never expected to experience, long past puberty and what he imagines the kind of conversation his father would have had with him if he had been alive when it happened. “I mean—I’m fine with the suppressants. I’m not interested in—I’m fine.” He is. Three to four times a year he just has to live with a few days of raging hormones shooting his sex drive through the roof—what’s so difficult about that? The suppressants mute the feeling enough that his horniness turns into perfectly bearable background noise. He doesn’t need his mother buying him a dildo to deal with it.

Fortunately, Krolia doesn’t push the subject. She lets him decide on how to handle his heats, reminding him occasionally that he can ask her anything. He doesn’t take her up on the offer despite his many burning questions but he does need to find the answers somewhere and that _somewhere_ he chooses is the internet—the space version of it at least.

It’s how he finds the video.

In retrospect, clicking on a link titled “Half-Galra Omega’s First Heat Off Suppresents” is a questionable decision but it’s not as if he grew up knowing what kind of porn was popular with aliens (tentacle porn would have been his first guess based on the things he overhears James say).

The video is poorly made, terribly acted, and makes Keith come twice.

He knows before watching it that being an omega means more than just being extra horny every now and then but knowing it and seeing it are entirely different things and watching the way the omega in the video takes a cock so huge it makes his stomach protrude is a revelation. He browses the website the video is hosted on and is overwhelmed by the options. In one video a group of alphas take turns fucking an omega in heat, the omega obediently keeping his ass raised in the air for easy access. In another, an omega fucks himself on what Keith learns is a heat toy and he can’t believe the size and girth of it and the way the omega is able to push a button to lock it into place to simulate a knot—he wants one, immediately, and is devastated when he finds out what the price of a heat toy that advanced goes for. He settles for a much simpler, cheaper toy to try out during his next heat.

For the first time since learning about his biology, Keith thoroughly appreciates what it has to offer. Krolia was wrong when she suggested a toy would help—it isn’t about helping, or “getting through his heat” as the educational resources he finds describes it, it’s about _enjoying_ his heat. Having something inside him, plugging him up, feels like an indulgent luxury. He never exactly dreaded his heats, but he did feel indifferent towards them. Now? He looks forward to them.

Of course, whenever Keith starts to feel at ease with his life something has to come and derail things. It’s what the universe does to him, no exceptions.

♠︎

Before he was a half-alien space humanitarian, Keith was a lonely teenage boy the world gave up on until one man decided to stick his neck out for him and believe in him despite all common sense.

That man—Shiro—being a young, hotshot pilot with a reckless streak and penchant for flying off cliffs in leather jackets kickstarts Keith’s libido in ways that are still embarrassing to recall. The worst but best of Keith’s memories is when Shiro would work on his hoverbike covered in grease with his shirt unbuttoned and his sleeves rolled up. An incident involving Shiro bending over and subsequently leaning against Keith to show him how to replace a faulty part replays in Keith’s fantasies for weeks. It’s fair to say Shiro’s entire existence serves as a sexual awakening for Keith.

But it’s not one he expects anything to come from. Maybe, in some moments, he wishes for it so hard it almost hurts, but Shiro doesn’t see him that way. He’s too young, too scrawny, he has too much baggage—the reasons Keith comes up with are endless. He has nothing to offer Shiro. He can only take from him, not give.

Then Shiro leaves and pilot error flashes across every viewscreen in the Garrison.

The grief that hits Keith sends him spiraling. His mourning isn’t quiet, it’s vicious and ugly and the Garrison wants none of it. He should be happy Shiro isn’t there to see his failure when he’s kicked out.

What happens next tests Keith in all the ways a person can be tested and by the end of it he’s left with one certain, immutable truth of his life: he loves Shiro and he’ll _always_ love Shiro.

But Shiro loving him back is a daydream Keith doesn’t even bother with. No, that isn’t it. He knows Shiro loves him because Shiro is a kind person, a good person, and he has enough love in him to spare some for Keith. But Shiro wanting him the way Keith wants him? That’s an impossibility. So he doesn’t think about how Shiro would react to his biology because it’s not something Shiro ever has to know.

“Keith, I know we’ve been through so much and maybe—maybe I’m too late.” The sunset in the desert is beautiful but Keith doesn’t even look at it; he only has eyes for Shiro. “But I have to say it. I love you, Keith.”

The confession is unexpected. Overwhelming in all the right ways. It doesn’t feel like a dream because Keith doesn’t know how to dream something so wonderful. Shiro tucks a strand of hair behind Keith’s ear. A nervous gesture. He’s nervous because he thinks Keith will reject him. Keith almost laughs, but he can’t because he’s not sure it would be a laugh when it leaves his throat.

So Keith kisses him because speaking is hard and he’s said the words before anyway, but he’s never been able to show the full truth of what he means.

It isn’t until later when the adrenaline calms down and the cloud he’s floating on evaporates that he remembers the part of him Shiro doesn’t know about. How somewhere down the line he’s going to have to explain the alien birds and bees to Shiro.

Fuck.

♠︎

The hand around Keith’s waist tightens its grip, holding him firmly in place. It’s big—the hand is stupidly big. Keith whimpers.

_Please_ , Keith begs.

A man laughs, light and teasing. _Patience_ , he says, his voice sending lighting down Keith’s spine, _yields focus_.

A knee nudges Keith’s legs apart. Wetness soaks through his underwear, pools underneath him staining the sheets. He thinks nothing of it until—

The man stops in shock.

“What’s going on?” Shiro asks.

“I—” Keith falters at the look in Shiro’s eyes. “It’s—the Galra—” The words won’t come.

Shiro pulls away from him in disgust.

“Please, I can explain,” Keith cries, but Shiro isn’t listening. He’s seen enough; he wants nothing to do with Keith anymore.

The rejection tears Keith apart, leaves him empty and aching.

Darkness swallows him.

Keith wakes up soaked in sweat. His hair clings to face matted and tangled. He groans and checks the time. It’s too early to be awake but after his nightmare, he’s hardly gunning to sleep again.

He drags himself out of bed and into the cabin’s renovated shower—a true luxury after years of communal bathing areas. Keith considered getting an apartment close to the Garrison but in the end, he didn’t see the point. He doesn’t spend enough time on Earth for the commute to be an issue and the wolf— _Kosmo_ , he reminds himself—likes it in the desert. They both do. The privacy is as much of a luxury as any of the renovations Keith has made.

The sun is starting to rise when Keith finishes drying his hair. The desert comes alive with color. The weather is perfect for jogging; Keith hums as he dresses. He ties back his hair and laces his shoes.

Kosmo runs circles around him once they’re outside, stopping to chase whatever catches his eye. He teleports here and there; Keith chides him, telling him if he teleports for every little thing he’s going to put on weight. Kosmo ignores his warning, as he always does. He has too much fun scaring coyotes half to death by teleporting next to them, entertained thoroughly by how much they aren’t expecting a cosmic horror nearly the size of a horse to appear from thin air.

Keith’s body aches. At first, he assumes it’s from pushing himself too hard. He slows down, taking a swig of water. The ache continues, undefined until it isn’t. The ache is inside of him, dull but relentless. It will get worse before it gets better.

His heat is starting, which explains the dream. His first heat while dating Shiro. Keith laughs or tries to, but the sound is garbled and weak. Kosmo teleports away from the lizard he’s chasing to nuzzle Keith’s side.

Keith wasn’t purposefully trying to hide this part of himself from Shiro—at first. It just didn’t matter yet. When Keith isn’t in heat he can control his Galra side, keep his claws from coming out, literally. Stay the human Shiro knows him as. But when he’s in heat, everything is so much more even with the suppressants that he ends up shifting.

Maybe, maybe, Shiro could get over that.

But what about the rest? What it actually means for Keith to be an omega? Keith thinks of his dream. The slick he produces is filled with pheromones attractive to alphas but Shiro isn’t an alpha—he’s human, and his very human response might very well be disgust with Keith’s body.

Keith squats and musses his hair in frustration. He needs to stop letting his anxiety get to him and just tell Shiro. Hiding is clearly taking a toll on him if his dreams are any indication and it hasn’t exactly been the best for their intimacy either. He thinks Shiro can sense his discomfort and fear because they haven’t done anything more than some heavy petting. Keith’s sexual frustrations are hitting peaks he didn’t think were possible. His heat starting is only going to make things exponentially worse.

Keith stands up. The sun shines down, warm and comforting.

Keith makes his decision. Today was going to be the day Keith tells Shiro he has a weird, alien secondary sexual characteristic that he really, really hopes Shiro is okay with because he loves him a lot and would very much appreciate if Shiro could fuck him, continuously, for three days straight. Immediately.

♠︎

Keith cancels his plans for the day to get ready for his heat. He lets Krolia know, as discreetly as he possibly can while still making his reasons clear, that he won’t be available for the next few days—can she watch Kosmo? _Of course_ , she says and Kosmo teleports his way over to her at Keith’s request.

Keith takes his extra blankets out of storage and makes sure he’s stocked on simple foods that won’t take any effort to prepare. He does the laundry, cleans the bathroom, and brings his box of heat toys out from under his bed (the collection has grown significantly since his first purchase and it makes his stomach roll, not unpleasantly, thinking about showing it to Shiro).

Shiro arrives in the afternoon. The leather jacket he’s dug up is different from the old one, modified for his floating arm, but it looks just as good, if not better, on him. When he climbs off of his hoverbike it’s like an image straight from Keith’s fantasies and Keith feels the first beginnings of his slick dripping from him in response. Keith flushes, glad that Shiro isn’t an alpha or no doubt he would be able to smell it.

“Keith.” Shiro smiles at him, a goofy grin that makes Keith smile in return.

_It’s going to be okay_ , Keith thinks. It’s going to be okay.

Keith had a plan of what to say and how to say it but the moment Shiro steps foot into his cabin it feels inadequate. Keith stops in the middle of the hallway, panic rising.

“Keith?” Shiro watches him expectantly. His cologne is almost overwhelming to Keith’s heat-heightened senses. Some woodsy and warm scent Keith can’t get enough of.

“I need to show you something.” Keith’s leggings feel stupidly tight. Why didn’t he think to change? All that time cleaning and preparing and he didn’t change out of his jogging gear? What was wrong with him.

“Okay,” Shiro says, patient and kind despite how clear it is that Keith is having a nervous breakdown.

After a few rounds of pacing, Keith manages to settle down enough to grab his datapad and drag Shiro into bed with him, albeit fully clothed, on top of his blanket nest. If Shiro notices Keith has more blankets on his bed than seems entirely necessary, he doesn’t comment on it.

“I want you to watch something. I had this, I don’t know, speech prepared but everything is so, I keep freaking out about it.”

“Keith, however you feel comfortable explaining things is what I want. If you don’t want to explain things at all, that’s fine too.”

Keith takes a deep breath, inhaling Shiro’s cologne, and relaxes. He finds a tamer video, something simple with two Galra that are fairly humanoid in appearance—no tails, no ridges on any cocks. Standard, vanilla alpha-omega porn.

He puts the datapad between them and presses play.

The omega whimpers, curled up naked in a nest of blankets not unlike the pile on Keith’s bed. He calls out for his alpha in Galran, nearly in tears. He needs his alpha, he needs him now, and luckily for him, his alpha soon comes into the room to help him through his heat.

The video moves quickly, the plot not exactly novel, and before long the omega presents himself for his alpha. This is the moment Keith has been waiting for; he watches Shiro’s reaction to seeing the slick dripping down the omega’s thighs as he holds himself open for his alpha’s appraisal and is met with nothing at all: Shiro watches the video with all of the interest he would give to a weather report.

Keith squirms uncomfortably. It isn’t the reaction he hoped for but it’s better than the alternative of disgust. So maybe Shiro doesn’t find Keith’s omega characteristics particularly appealing—he’s human, it’s to be expected. As long as he doesn’t run away screaming, Keith will count it as a victory.

“Keith, uh.”

Keith startles from his thoughts.

On the datapad, the alpha pounds into the omega who mewls in satisfaction. Keith wishes bitterly for that to be him before chastising himself for the thought. Shiro is under no obligation to fuck him, and just because his heat is making him antsy doesn’t mean he gets to forget that.

Keith turns the datapad off.

“Sorry, I thought—well I was hoping.” Keith shakes his head. “I guess I’ll just say it, um, I’m not too sure how much of that actually made sense to you but the Galra—they have this thing that humans don’t. Most aliens don’t, actually, and it’s probably why there are so many half-Galra running around and not a lot of half-anything else. Galra, they’re—we’re—divided into alphas, betas, omegas.” Maybe Keith should have just translated the booklet Krolia gave him and given it to Shiro. It would have been a lot less mortifying.

“I know,” Shiro says, his face pink.

“You—know?”

“When I was in captivity—well, long story short. I know. And, um. I think—you’re an omega, aren’t you?” He blurts out the last part in one breath, his mouth clamming shut afterward as if he’s given away a secret he shouldn’t have.

“Uh, I am, yeah.” This isn’t going how Keith expects. He feels off balance. Dizzy almost. Shiro’s cologne seems to be even stronger than when he first entered the cabin—like he reapplied it when Keith wasn’t looking.

“I can smell you,” Shiro admits, his face bright red like he’s the one in heat, not Keith.

“Huh?” The conversation isn’t making any sense.

“I didn’t before this body. I think—no, I _know_ Haggar did something to it. I wanted to tell you, but I was afraid and I didn’t understand what was happening. I told you, I knew about the Galra from captivity, but what I knew—Keith it wasn’t pretty.” Keith sets the tablet aside and places a palm against Shiro’s face. He as an idea of the horrors Shiro alludes to—there are darker videos he avoids—and he wishes that wasn’t how Shiro learned about these things. “I didn’t want to be like that, Keith. I didn’t want to hurt you.”

“You’re not going to hurt me, Shiro. I want you, I want this.” He drags Shiro’s hand between his legs where his slick is starting to soak through his leggings.

“Keith,” Shiro groans, “Are you sure?” It’s a redundant question as far as Keith is concerned. Yes, he is currently aching with a biological need to be touched and filled but he always wants Shiro in some capacity. It’s hard to believe Shiro doesn’t realize that.

“Yes, I’m sure.” Keith grinds into Shiro’s palm. ”I’m on suppressants. They make my heats milder and, uh, double as birth control—not that I’ve needed them for that yet.”

Shiro presses him into the mattress, his weight settling over Keith pleasantly, and kisses him. Keith digs his nails into Shiro’s shoulders; their kisses turn filthy and wet. Keith squirms underneath him, chasing after any friction he can get. Shiro’s tongue catches on something and he pulls back in surprise but there’s no disgust on his face, only a curiosity that makes Keith feel strangely wanted.

“You have fangs,” Shiro says, sounding pleased.

“Oh.” Keith pulls a hand back to check and yeah—it’s as he suspected: his nails have turned into claws. “That probably means,”—Keith gestures at his face—“my eyes, too.”

“You’re amazing, Keith.” He touches the points of Keith’s fangs. “That’s really hot.”

Slick pours from Keith at the attention. Shiro notices—he must smell it thanks to Haggar’s modifications. Keith’s heart races.

“I think we should get this off you,” Shiro says, tugging at the waistband of Keith’s leggings.

Keith nods in agreement. He makes fast work of his clothing—if he rips some of it in the process with his claws, so be it.

Shiro too, he takes off everything but his boxers, much to Keith’s dismay.

“You know how I said Haggar did something to this body?”

Keith nods. “Yeah?”

“I have a knot,” Shiro says.

Keith’s eyes go wide. “You’re an alpha?”

“Yes? Maybe?” Shiro’s voice is shy and uncertain. “I don’t know if I’m really like a Galra alpha, or just something similar.”

Shiro’s cologne isn’t really a cologne. _It’s his scent._ Keith breathes it in, lets it surround him. He’s smelled other alphas before—it’s impossible not to have working with the Blades—but it’s never been like this. Comforting and addictive.

“Want you, Shiro. Now.” The lust he can usually keep at bay crashes in a desperate desire to be filled, to be knotted. He never dreamed it could happen—he didn’t want anyone but Shiro and Shiro was human, he couldn’t give that to him no matter how hard Keith begged for it. Except Keith’s assumptions were wrong. Shiro can fuck him full and keep that feeling there.

Shiro peels off his boxers and Keith makes a sound he hopes is sexy and not just needy at the sight of his cock. It’s bigger than Keith’s wildest imaginations—an alpha cock reacting to an omega in heat.

“Please,” Keith begs.

“Patience.”

“Don’t you dare say ‘yields focus,’” Keith snaps.

Shiro chuckles and grabs Keith’s hips, the tip of his cock at Keith’s entrance. “Wasn’t going to, I promise.”

Shiro slides his cock into Keith’s hole and any quip Keith might make dies in his throat. All of the slick gushing out of him makes it pathetically easy for Shiro’s cock to breach him despite the tight fit. Right now, he was made for this.

Shiro sets a brutal pace, fucking Keith with all his strength. It’s exactly what Keith needs. He can more than take it with his Galra side out in full force. If he isn’t careful Shiro is going to be covered in bruises from where Keith grabs onto him.

Being fucked by Shiro is nothing like fucking himself on heat toys. As good as they feel it’s entirely different to be surrounded by Shiro’s scent, to feel the heat of him, to be taken care of by him, instead of being alone.

“Want your knot.”

It’s Shiro’s turn to make a needy sound. He flips Keith over, pushing him onto his stomach and pulls up Keith’s hips to continue fucking him.

Keith wants to see Shiro’s face when he comes. Objectively, he knows when Shiro knots him it will be more comfortable like this, but he _wants_ to see him. He tries to turn around, to angle his head just so—

Shiro grabs a fistful of Keith’s hair and tugs.

All thoughts of turning around die abruptly in Keith’s mind. Shiro pulls Keith’s head back, making his back arch. Keith comes moments later, his hole squeezing around Shiro’s cock.

Something pushes into Keith, expanding him. As it grows, Keith begins to feel the fullness he’s been chasing after.

Speared on Shiro’s cock, Keith cries out in bliss, coming again when Shiro begins to unload inside him, his knot locking them together and keeping Shiro’s come from leaking out.

Keith feels complete.

Shiro lays them on their side and kisses along Keith’s shoulder. “Keith,” he murmurs softly into the crook of Keith’s neck. He places his left hand against Keith’s stomach, at the bulge there. The sight of it makes Keith clench around Shiro’s cock, as if his body is determined to milk every last drop from Shiro.

“Keith?”

“Mmm, yeah?” It’s a struggle to form words. He doesn’t know if it’s finally getting knotted that’s done it or if it’s just from being like this with _Shiro_ , the man he’s wanted since he was a teenager.

“How do you feel?” His voice is small and hesitant; it doesn’t suit him.

“Full,” Keith says because it’s the truth.

Shiro makes a strangled noise.

Keith laughs and snuggles closer to Shiro. “What? You asked. Feeling full is pretty much the entire goal of a heat so congratulations, you’ve fulfilled your duties as an alpha.”

“This isn’t what I thought our first time would be like.”

Keith tenses. “Oh, uh. Sorry about that.”

“No, not like—I didn’t mean it in a bad way. You’re amazing, Keith.”

Keith’s heart pounds; he knows it’s stupid to feel like he’s being rejected when Shiro’s knot is still inside him but he can’t help it. “It’s okay if you think this is weird. I know it’s a lot.”

“I don’t. Nothing about you is weird, Keith. Really. I guess I should make myself clear—this is something I’ve thought about since before we knew you were Galra so I didn’t picture it happening like this, that’s all.”

Keith looks behind him in shock. How long has Shiro wanted this, wanted him?

“Shiro, how long have you been—" Shiro rolls his hips; the tiny thrust has Keith moaning. “Ah—! Shiro, don't think you can just—" Shiro’s knot is going down, giving him the space he needs to move again. Every small thrust is a jolt to Keith's overstimulated system. If Shiro thinks it’s enough to make Keith forget he just admitted to fantasizing about him before they even knew he was Galra, he’s in for a surprise later.

Because they will be talking about this later. Keith wants to hear all about how Shiro pictured them fucking on every planet they ever visited. How he wanted to take Keith in the Castleship so many times. After that, they can get started on Keith’s fantasies. His horny, seventeen-year-old self had some particularly genius ideas.

With Shiro’s knot nearly gone Keith is able to twist himself around to look at Shiro properly.

“Shiro—thank you.”

“Are you thanking me for fucking you?”

Keith rolls his eye; the effect is ruined when seconds later his tongue mysteriously finds its way into Shiro’s mouth.

With great difficulty, he eventually manages to reply. “Thank you for believing me. For not freaking out when I made you watch some weird alien porn instead of just explaining to you that a few times a year I just really, really want to be fucked.”

“Only a few times a year? Too bad, I could get used to this.”

Keith bites Shiros’s lip. His fangs are sharp enough to draw a pinprick of blood. “Sor—,” he starts; the apology dies when he sees the expression on Shiro’s face. It’s not the look of someone that minds being bitten.

“You liked that,” Keith says.

Shiro doesn’t deny it.

Keith smiles the wide grin of a predator. “What else do you like? Tell me.” He digs his claws into Shiro’s scalp, thrilled when it gets Shiro to shudder.

“You,” Shiro answers honestly, nearly breathless. “I like you.”

“Oh—me too. I want you, Shiro. Not just now, but always.”

Shiro pulls them up until Keith is in his lap. A mixture of slick and come dribbles out of Keith; Shiro’s knot is no longer there to keep him plugged full. The omega part of Keith mourns the loss but he knows Shiro will fill him again and soon.

His worry and fears are as distant and unreal as his nightmares of Shiro rejecting him. It’s not some omega instinct that makes him feel safe and loved by Shiro. All he needs to do is open his eyes and look to see the truth of it.

**Author's Note:**

> baby's first ABO sure is a thing that's happened now 🙈


End file.
